Tart cards are the means by which many London prostitutes advertise their services. Step into almost any central London phone box and you can contemplate up to 80 cards inviting you to be tied, teased, spanked or massaged.

Even if a police crackdown, the internet and the increasing use of mobile phones suggest their days are numbered, tart cards are still so pervasive they are now regarded as items of accidental art and have something of a cult following. Once on the periphery of design, tart cards have influenced the work of many mainstream artists such as Royal Academician Tom Phillips and Sex Pistols designer Ray and Nils Stevenson.

In conjunction with St Bride Library and Type, we asked designers – from students to superstars – to find the tart hiding in every type and create their own graphic numbers. Along with a selection in the magazine, all 450 cards can be viewed here.